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mux.c

/*
 * linux/arch/arm/plat-omap/mux.c
 *
 * Utility to set the Omap MUX and PULL_DWN registers from a table in mux.h
 *
 * Copyright (C) 2003 - 2005 Nokia Corporation
 *
 * Written by Tony Lindgren <tony.lindgren@nokia.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <asm/system.h>
#include <asm/io.h>
#include <linux/spinlock.h>
#include <asm/arch/mux.h>

#ifdef CONFIG_OMAP_MUX

#define OMAP24XX_L4_BASE      0x48000000
#define OMAP24XX_PULL_ENA     (1 << 3)
#define OMAP24XX_PULL_UP      (1 << 4)

static struct pin_config * pin_table;
static unsigned long pin_table_sz;

extern struct pin_config * omap730_pins;
extern struct pin_config * omap1xxx_pins;
extern struct pin_config * omap24xx_pins;

int __init omap_mux_register(struct pin_config * pins, unsigned long size)
{
      pin_table = pins;
      pin_table_sz = size;

      return 0;
}

/*
 * Sets the Omap MUX and PULL_DWN registers based on the table
 */
int __init_or_module omap_cfg_reg(const unsigned long index)
{
      static DEFINE_SPINLOCK(mux_spin_lock);

      unsigned long flags;
      struct pin_config *cfg;
      unsigned int reg_orig = 0, reg = 0, pu_pd_orig = 0, pu_pd = 0,
            pull_orig = 0, pull = 0;
      unsigned int mask, warn = 0;

      if (!pin_table)
            BUG();

      if (index >= pin_table_sz) {
            printk(KERN_ERR "Invalid pin mux index: %lu (%lu)\n",
                   index, pin_table_sz);
            dump_stack();
            return -ENODEV;
      }

      cfg = (struct pin_config *)&pin_table[index];
      if (cpu_is_omap24xx()) {
            u8 reg = 0;

            reg |= cfg->mask & 0x7;
            if (cfg->pull_val)
                  reg |= OMAP24XX_PULL_ENA;
            if(cfg->pu_pd_val)
                  reg |= OMAP24XX_PULL_UP;
#if defined(CONFIG_OMAP_MUX_DEBUG) || defined(CONFIG_OMAP_MUX_WARNINGS)
            {
                  u8 orig = omap_readb(OMAP24XX_L4_BASE + cfg->mux_reg);
                  u8 debug = 0;

#ifdef      CONFIG_OMAP_MUX_DEBUG
                  debug = cfg->debug;
#endif
                  warn = (orig != reg);
                  if (debug || warn)
                        printk("MUX: setup %s (0x%08x): 0x%02x -> 0x%02x\n",
                                    cfg->name,
                                    OMAP24XX_L4_BASE + cfg->mux_reg,
                                    orig, reg);
            }
#endif
            omap_writeb(reg, OMAP24XX_L4_BASE + cfg->mux_reg);

            return 0;
      }

      /* Check the mux register in question */
      if (cfg->mux_reg) {
            unsigned    tmp1, tmp2;

            spin_lock_irqsave(&mux_spin_lock, flags);
            reg_orig = omap_readl(cfg->mux_reg);

            /* The mux registers always seem to be 3 bits long */
            mask = (0x7 << cfg->mask_offset);
            tmp1 = reg_orig & mask;
            reg = reg_orig & ~mask;

            tmp2 = (cfg->mask << cfg->mask_offset);
            reg |= tmp2;

            if (tmp1 != tmp2)
                  warn = 1;

            omap_writel(reg, cfg->mux_reg);
            spin_unlock_irqrestore(&mux_spin_lock, flags);
      }

      /* Check for pull up or pull down selection on 1610 */
      if (!cpu_is_omap15xx()) {
            if (cfg->pu_pd_reg && cfg->pull_val) {
                  spin_lock_irqsave(&mux_spin_lock, flags);
                  pu_pd_orig = omap_readl(cfg->pu_pd_reg);
                  mask = 1 << cfg->pull_bit;

                  if (cfg->pu_pd_val) {
                        if (!(pu_pd_orig & mask))
                              warn = 1;
                        /* Use pull up */
                        pu_pd = pu_pd_orig | mask;
                  } else {
                        if (pu_pd_orig & mask)
                              warn = 1;
                        /* Use pull down */
                        pu_pd = pu_pd_orig & ~mask;
                  }
                  omap_writel(pu_pd, cfg->pu_pd_reg);
                  spin_unlock_irqrestore(&mux_spin_lock, flags);
            }
      }

      /* Check for an associated pull down register */
      if (cfg->pull_reg) {
            spin_lock_irqsave(&mux_spin_lock, flags);
            pull_orig = omap_readl(cfg->pull_reg);
            mask = 1 << cfg->pull_bit;

            if (cfg->pull_val) {
                  if (pull_orig & mask)
                        warn = 1;
                  /* Low bit = pull enabled */
                  pull = pull_orig & ~mask;
            } else {
                  if (!(pull_orig & mask))
                        warn = 1;
                  /* High bit = pull disabled */
                  pull = pull_orig | mask;
            }

            omap_writel(pull, cfg->pull_reg);
            spin_unlock_irqrestore(&mux_spin_lock, flags);
      }

      if (warn) {
#ifdef CONFIG_OMAP_MUX_WARNINGS
            printk(KERN_WARNING "MUX: initialized %s\n", cfg->name);
#endif
      }

#ifdef CONFIG_OMAP_MUX_DEBUG
      if (cfg->debug || warn) {
            printk("MUX: Setting register %s\n", cfg->name);
            printk("      %s (0x%08x) = 0x%08x -> 0x%08x\n",
                   cfg->mux_reg_name, cfg->mux_reg, reg_orig, reg);

            if (!cpu_is_omap15xx()) {
                  if (cfg->pu_pd_reg && cfg->pull_val) {
                        printk("      %s (0x%08x) = 0x%08x -> 0x%08x\n",
                               cfg->pu_pd_name, cfg->pu_pd_reg,
                               pu_pd_orig, pu_pd);
                  }
            }

            if (cfg->pull_reg)
                  printk("      %s (0x%08x) = 0x%08x -> 0x%08x\n",
                         cfg->pull_name, cfg->pull_reg, pull_orig, pull);
      }
#endif

#ifdef CONFIG_OMAP_MUX_ERRORS
      return warn ? -ETXTBSY : 0;
#else
      return 0;
#endif
}
EXPORT_SYMBOL(omap_cfg_reg);
#else
#define omap_mux_init() do {} while(0)
#define omap_cfg_reg(x) do {} while(0)
#endif      /* CONFIG_OMAP_MUX */

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